And the president’s climate change address at Georgetown University hasn’t cleared anything up for either side of the Keystone cause. Big oil and environmentalists alike were puzzled, USA Today’s David Jackson reports:

Much of the Obama befuddlement centers on different interpretations of one part of his speech, writes Forbes’ staffer Christopher Helman: “Obama said that the Keystone XL pipeline would only be approved if it ‘does not significantly exacerbate the problem of carbon pollution.’”

“Exacerbate” isn’t exactly and exacting term, Helman writes.

It means to aggravate, to sharpen, or to make a bad problem worse. The anti-Keystone crowd naturally thinks that the pipeline, or anything that aids in the transport of oil sands crude, would exacerbate carbon emissions. But that’s not what the State Department found.

Politico’s Talia Buford focused on another wiggly word: “significantly,” and thinks the speech hinted at an eventual approval of the pipeline, which would transport crude from the tar sands of Albetra through Oklahoma to refineries on Texas’ Gulf Coast.

… he announced what sounded like a daunting environmental threshold for the controversial Keystone XL oil pipeline — that the project can’t go forward if it would “significantly” increase greenhouse gas emissions.

What he didn’t mention: His own State Department has already indicated that the pipeline can meet that standard.